This application represents a three-year competing revision supplement to research grant R01 DC010494. The central focus of the parent grant was to investigate the potential of optimization of fitting parameters in cochlear implants. This was proposed with the use of a portable research speech processor that allows users to: (a) change MAP parameters based on two outcome measures, namely quality and intelligibility (b) customize the MAP to different listening situations for maximum benefit, and (c) collect feedback and recordings of real acoustic signals for further analysis. Unilateral, bilateral and bimodal users will participate in double-blind field trials to assess the true benefit of a portable speech processor that can be easily customized by the users to optimize their listening experience. For portable cochlear implant speech processor, the PDA platform, which was developed in our lab under an NIDCD contract, will be used. The PDA processor was recently approved by FDA for IDE clinical trials and distributed to 8 research labs and clinics. Given that the PDA processor is currently in IDE clinical trials, clinical monitoring has to be set in place and ongoing with the research studies proposed in the parent R01. Support for the cost of clinical monitoring is requested with the current competing revision application. Support for one full-time engineer who will be responsible for maintaining all IDE-related documentation from the participant clinics and for providing technical support for all software running on the PDA processor is also requested. This supplemental funding will enable the PI to pursue the goals of the original parent R01 application and remain compliant with FDA regulations. PUBLIC HEALTH RELEVANCE: The outcomes of this work can greatly benefit the overall quality of life for a large number of cochlear implant users. Cochlear implant users who are able to communicate effectively in noisy environments have greater opportunity for integration into mainstream education, increase their productivity at home or work and contribute more in the nation's economic growth and competitiveness.